Thermal dye sublimation printing uses heat to transform colored dye on a donor ribbon into a gas which gets absorbed by a receiver media. This imaging process has the property that once a point of the thermal donor media has been used it cannot be reused, as insufficient amounts of dye remain for a second use. Thermal donor media comes in standard configurations such as a roll composed of a series of interleaved cyan, magenta, and yellow (CMY) panels. Not all of a given panel is consumed in a given print cycle. Some applications repeatedly print images of the same size and in the same location. The size is significantly smaller than the size of the CMY panels. Printers are produced which can print using any region of the CMY panels. Hence, a panel of thermal donor media is used a single time. If a repetitive printing application uses a well-defined region of the printable area and the image area is significantly smaller than a panel, there is a large amount of donor media which is not used and becomes waste. What is needed is a means for enabling less of each thermal donor media sheet to go unused.
The prior art teaches how to rewind thermal donor ribbon where the ribbon is multi-strike; that is, the same location of a ribbon can transfer dye repeatedly with minimal loss of quality. Some multi-strike ribbons achieve this through the use of a plurality of dye layers. U.S. Pat. No. 4,924,250 by Herbert, et al., and assigned to Alcatel Business Systems, Ltd., teaches how to rewind a multi-strike thermal donor ribbon containing a single dye. U.S. Pat. No. 4,496,955 by Maeyama, assigned to Sony, describes a process for a multi-strike thermal donor media composed of a repetitive sequence of CMY panels for color printing. The number of rewinds for a given CMY panel sequence, however, is predetermined.
Some thermal donor ribbon cannot be addressed multiple times as the initial transfer of dye alters the thermal donor transfer properties. If such a thermal donor ribbon were used, the printing would be defective and unreliable. In the case of such thermal donor ribbons, what is needed is a control means to position the donor ribbon and receiver media as to insure presentation of fresh regions of the rewound thermal donor to the thermal print head for transfer to the desired thermal receiver location.